1. Field of the Invention
This invention pertains to the use of a unitary glass fiber in an infrared counter measure system in connection with an infrared seeking missile threat to convey a high power optical signal from a laser to a guidance system in order to break lock of the missile threat to the target that is a movable platform.
2. Description of Related Art
Anti-aircraft missiles can be categorized in two categories: active and passive. Missiles with active guidance are guided by external signals, which can be in the from of a radar on the missile, or guided by guidance information sent by the launching plane or ground launcher. Missiles with passive guidance are guided by signals given off by the plane or another target they are tracking. For example, a Sidewinder missile tracks the heat (infrared energy) of exhaust of the target.
This invention pertains to the use of a unitary infrared transmitting glass fiber from a laser to and within a jam head and in a missile protection system against a passively guided missile to convey a disabling optical signal to the missile in order to neutralize its objective.
The article in the publication “NRL Review” for September 2000 discloses the use of segmental glass fibers in a jam head of an infrared counter measure system. The article discloses that the IR-transmitting optical fibers are a natural choice for a compact low-cost optical device from the laser to the jam head. The article discloses the use of chalcogenide glasses, such as arsenic sulphide, which transmit in the 2-5 micron wavelength region. FIG. 8 of the article shows the use of three segmental glass fibers in and leading to the jam head. With an optical loss of 17% per face and 31% per rotary joint causes degradation in the signal that is intended to be transmitted to the IR guidance system of the threat missile.